RGtk2 (version 2.20.31)

cairoSetDash: cairoSetDash

Description

Sets the dash pattern to be used by cairoStroke. A dash pattern is specified by dashes, a list of positive values. Each value provides the length of alternate "on" and "off" portions of the stroke. The offset specifies an offset into the pattern at which the stroke begins.

Usage

cairoSetDash(cr, dashes, offset)

Arguments

cr

[Cairo] a cairo context

dashes

[numeric] a list specifying alternate lengths of on and off stroke portions

offset

[numeric] an offset into the dash pattern at which the stroke should start

Details

Each "on" segment will have caps applied as if the segment were a separate sub-path. In particular, it is valid to use an "on" length of 0.0 with CAIRO_LINE_CAP_ROUND or CAIRO_LINE_CAP_SQUARE in order to distributed dots or squares along a path. Note: The length values are in user-space units as evaluated at the time of stroking. This is not necessarily the same as the user space at the time of cairoSetDash. If num.dashes is 0 dashing is disabled. If num.dashes is 1 a symmetric pattern is assumed with alternating on and off portions of the size specified by the single value in dashes. If any value in dashes is negative, or if all values are 0, then cr will be put into an error state with a status of CAIRO_STATUS_INVALID_DASH.